Fire Sprinklers

Fire Sprinkler Systems 

At Ultrasafe we are specialists in design, installation, commissioning and servicing of domestic and residential fire sprinkler systems. We have many years of experience and numerous happy customers, case studies and testimonials. 

Fire sprinklers not only make a property safer but also enable more open plan designs. The design and installation details of a fire sprinkler system depends on the size and style of the property as well as the nature of its use and of course on the water supply. Broadly there are two types of fire sprinkler system either it can be fed from the mains or from a tank and pump. 

Mains Fed Fire Sprinklers

As the name suggests this is a fire sprinkler system fed directly by the town water main. As such there is no need to store the water in a tank or pump the water around the system. However a town water main fire sprinkler system is reliant on the consistency of water pressure provided by your local utility company.

To feed a fire sprinkler system the water main must satisfy the following criteria:

  1. There must be a dedicated* 32-50mm (cat 1), 50mm (cat 2), 50-63mm (cat 3) incoming water main into the property.
  2. The water main must be unmetered – this is a requirement of the British Standard.
  3. Water pressure and flow must be determined by the design and hydraulic calculation, typically between 2.5 and 4 bar
  4. The water flow rate varies between litres per minute (Cat 1, 1 head) and 240 litres per minute (Cat 3, 4 heads).

If the town water mains supply in your building can not meet these criteria and a new supply is not an option then a stored water supply should be used.

 Pump and Tank Fire Sprinklers – this system is fed from water stored in a tank and pumped to the sprinklers.

Ultrasafe offer servicing, testing, maintenance and servicing on all our fire sprinkler systems for more information please go to our page on Servicing and Maintenance of Fire Sprinklers.

*If a dedicated supply cannot be provided then a priority demand (solenoid) valve can be fitted. This will divert water to the fire sprinkler system upon activation. However, an additional 25 litres per minute will be required on top of the design duty.

Pump & Tank Fire Sprinkler Systems

fire sprinkler tank

Fire sprinkler tank & self testing pump

If the town water main does not meet the criteria cannot then your sprinkler system will need to be fed from a stored water supply. From here we attach a self-testing pump to ensure that the required water can be supplied to all the sprinkler heads. 

Fire sprinkler tank size calculations

The size of the tank is designed by the hydraulic calculations of the system using the number heads determined by the category. BS9251:2014 states typical volume of tanks as Cat 1 1500 litres, Cat 2 3000- 4500 litres and Cat 3 6000-9000 litres.

Should a tank have a proven infill (through a 32mm @ over 1.2 litres per second (cat 1) 50mm (cat 2-3) @ 2 litres per second) then the water storage capacity could be reduced by 40% assuming building control are satisfied with this.

Existing water tanks can be used assuming that the above volumes can be guaranteed for the use of the sprinkler system. A boosted mains water supply system can also be utilised if sufficient water storage is available.

The image shows a domestic water tank and self-testing pump. This system will provide the building with a 10 minute operational run time. (In residential installations the system will provide the building with a 30 minute operational run time).

Benefits of Fire Sprinklers

Saving Lives, Protecting Property

The ultimate benefit that a fire sprinkler system brings is that it saves lives and protects property. No one in the UK has ever died from a fire in a building with an installed and fully maintained fire sprinkler system. A sprinkler system will also bring many additional benefits:

  • Contain, control and quite often extinguish a fire.
  • Use less water (some 400x less) then fire and rescue services.
  • Significantly reduce fire damage.
  • Provide an audible alarm to alert occupants of activation.
  • Provide an eco-friendly fire solution
  • Reduce the amount of toxic and harmful emissions produced as a result of combustion.
  • Operate 24/7 giving you complete and total peace of mind.
  • Significantly reduce smoke damage.

Fitting a fire sprinkler increases flexibility in building design

The benefits of fire sprinkler system do not stop at life safety.  They can also open up many design opportunities through trade-offs.

The design trade-offs of fire sprinklers systems enable architects more freedom in the design of a building and allows original architecture to be respected in the restoration or conversion of older or period properties. Key design trade-offs that can be enjoyed with the incorporation of a fire sprinkler system in a building include:

  • Elimination of a secondary means of escape
  • Extension of travel distances
  • Reduction of boundary distances
  • Greater open planning freedoms on ground floor levels
  • A reduction in fire resistance compartmentalisation

Click here to download a fact sheet showing how a fire sprinkler system fits into the wider context of building regulations as well as trade offs

Case Studies


Concealed Fire Sprinkler Heads

Concealed Fire Sprinkler Heads are slim, discreet and modern in design and generally go unnoticed by residents. With a contemporary white finish, when installed on a white ceiling they become part of the decor. What do Fire Sprinkler Heads look like?  Ultrasafe Fire Sprinkler Heads are attractive and sit almost...

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Latest News


What triggers fire sprinklers and can they go off accidentally?

What triggers fire sprinklers? Fire sprinklers are triggered by the air around the sprinkler head in the room reaching a certain temperature. Usually the temperature to trigger a residential sprinkler is 56oC.  Heat of 63oC is required to trigger fire sprinklers in larger warehouses where lots of heat is generated...

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What are the British Standards for Sprinkler Systems?

There are two British Standards for sprinkler systems in operation: BS 9251: 2014 – Sprinkler Systems for Residential and Domestic Occupancies. (formerly BS 9251: 2005) BS EN 12845:2004 – Fixed Fire Fighting Systems. Automatic Sprinkler Systems. Design, Installation and Maintenance.  If you would like to read more about BS 9251 or read more about the product requirements...

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What is a domestic property and a residential property with regard to fire sprinkler regulations?

Domestic or Residential Property? A domestic property in BS 9251:2005 is defined as dwelling that has no more than one family unit. This could be a house, individual flats and maisonettes. BS 9251:2005 requires that a sprinkler system must be designed to ensure that two sprinkler heads can be fed by...

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What about legionnaires in fire sprinklers?

Legionnaires in fire sprinklers is not a problem, if systems are designed and maintained correctly. The pipe work which is installed (CPVC) is of a food quality standard, negating legionella possibilities. Technical Briefing Note 14 (May 1999), produced by the LPC “Legionella and Fire Fighting Systems” states, “The conditions normally...

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Fire Sprinkler System Cost

What is the approximate cost of a fire sprinkler system? We are often asked ‘How much does a Fire Sprinkler System cost?’ Of course it is very difficult to answer without knowing more details of the project. However we recognise that it is difficult to make the decision to seriously consider...

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Fire Sprinkler Specialists

Southern Office

Unit 1 Bowlings Corner, Marley Lane, Battle, East Sussex, TN33 0RE

Northern Office

5 Snape Road, Macclesfield, Cheshire, SK10 2NZ

#FireSuppression Systems for New Build Homes & Renovations We’re here to help #Designers and #Architects plan the best system for their clients. Bespoke systems to current regulations & the highest mechanical design Call us: ☎️01625 467245 ☎️ Or Email 📩

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